Phase changing electrical circuit arrangement



l 1941- s. w. H. w. FALLOON E-rm. 54,734

PHASE CHANGING ELECTRICAL CIRCUIT ARRANGEMENT Filed Jan. 2l 1939 7 INVENTORS SHIRLEY WALDRON HUGH WOLSELEYFALLOOA BYGEORG E/MLINGTON ATTORNEY Patented Sept. 2, 1941 PHASE CHANGING ELECTRICAL CIRCUIT ARRANGEMENT Shirley Waldron Hugh Wolseley Falloon, Chelmsford, and George Millington, London, England, assignors to Radio Corporation of America, a

, corporation of Delaware Application January 21, 1939, Serial No. 252,154

In Great Britain January 22, 1938, 7 Claims. (curs-44) "This invention relates to phase changing arrangements and has for its object to provide a variable phase changing arrangement which can be utilized to change the phase of an applied alternating E; M. F. by an amount which is accurately' dependent upon the adjustment of the said arrangement; Such a variable, calibrated phase changer is of use for many purposes and in particular in those known radio signalling condenser 8 and also to one end of the other stator coil 2' through a second tuning condenser 9. The other input terminal 1 is connected to the remaining ends of the two stator coils I, 2 through two separate resistances ll), II. The tuning condenser 8, 9 may be variable and, if so, may be gang controlled if desired. Thus each stator coil forms part ofa tuned circuit, the circuits being resonant respectively at frequensystems in which the directivity of an aerial sys- 10 cies F+f and F-f" where F is the frequency of tem is varied in the vertical or in the horizontal the current whose phase is to be shifted and f plane by adjusting the phases of the currents and f" are frequencies such that, if bothtuned infeeders to or from individual a'erial units formcircuits are fed with the frequency F the currents ing part of an aerial system. in the two stator coils will be in phase quadrature According to this invention a variable phase and of equal amplitude. The two rotor coils 3, 4 changing arrangement comprises two mutually are connected together at one end, the junction perpendicular inductance coils each forming part point being connected (through a suitable bias ofa tuned circuit, said circuits being resonant source l2 if required) to the common cathode at two frequencies'on opposite sides of the frepoint l3 of two push-pull connected valves l4, quency of the alternating current whose phase I5 (shown as pentodes, but, of course, other is to be adjusted said two frequencies being such suitable valves might be used) whose input grids that the phases of the currents in two said coils l6, ll are connected one to the free end of one will be in phase quadrature if said circuits are rotor coil 3 and the other to the free end of energized'by said alternating current; two furthe other rotor coil 4. Each rotor coil is tuned ther mutually perpendicular coils, said first menby a condenser l8 or l9. Phase shifted output tioned two coils forming the stator (or the rotor) is taken via tuned circuit 20 and output coil 2| of avariable transformer and said further two from the push-pull anode circuit-of the two coils" forming the'rotor (or the stator) of said valves l4, l5. variable transformer; means for applying said With this arrangement the phase relation bealternating current'to the first mentioned two tween the input and output currents will depend coils and means for taking off alternating curupon and be accurately proportional to the angurerit output from the further two coils the arlar setting of the variable transformer and it rangement being such that the relative phase may be shown that, by reason of the use of the between the input and the output alternating two similar mutually perpendicular rotor coils, currents depends upon the angle of the rotor the absorption of energy by the rotor circuit will relative to'the stator. The effects of stray canot disturb the quadrature relationship between pacities must, of course, be taken into account the currents in the stator coils, for, so long as and'the above mentioned resonant circuits are the variable transformer iswound to obey the to be'taken as resonant to the frequencies stated usual law coupling=K sin 0 (where K when the apparatus is fully assembled and stray 40 is a constant and 0 is the angle of rotary capacitiesare playing their parts. displacement of the rotor with respect to -The invention is illustrated in the accompanythe stator) the total amountof energy absorbed ing schematic and diagrammatic drawing, in by the rotor circuit from the stator circuit will whichFigure 1 illustrates an embodiment of the not vary with rotation of the rotor. invention and Figure 2'is a modification thereof. Obviously, if desired, the functions of the rotor Referring to Figure 1 which shows diagramand stator can be interchanged, i. e. input may matically'one way of carrying out this invenbe applied to the rotor and output taken-from tion, there is provided a variable transformer the stator. 7 comprising two mutually perpendicular stator Where a phase changer is required between coils l, 2 and within said coils, two mutually persuccessive stages of valve amplification the input pendicular rotor coils 3, 4 the two rotor coils alternating potential may be applied in push-pull being rotatable together about an axis 5 which to the grids of two valves constituting one stage, is diametrical to all four coils. The terminal 6 each valve anode circuit containing one or other I of a pairof input terminals 6, l is connected to of the two stator coils l, 2 of a variable transone end of one stator coil "I through a tuning 5 former as above described, each said stator coil being in parallel with a series connected combination of resistance and tuning condenser (8, H3 or 9, I l) The rest of the circuit is as before, the second valve stage being constituted by the two push-pull valves l4, above described as connected to the rotor coils (3, A) This arrangement allows of easy correct matching of the amplifier valves. Alternatively, and as shown in Figure 2, the input alternating potential may be applied in the grid circuit of a valve 22 whose anode circuit contains the primary 23 of a tuned transformer 23, 24 the secondary 24 feeding into the stators of the variable transformer. The ratio of the transformer should be such as to provide a satisfactory impedance match between the valve 22 and the load constituted by the series tuned stator circuits in parallel. Corresponding parts in Figures 1 and 2 are given the same references, the phase changer being shown purely diagrammatically in Figure 2.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is:

1. A variable phase changing arrangement comprising a pair of inductance coils having a common diameter and disposed at an angle to each other, and forming the stator of a variable transformer, each coil forming part of a tuned circuit, said circuits being so dimensioned that the phase angle between the currents therein when energized by alternating current is equal to the angle between said coils, a second pair of mutually perpendicular coils forming the rotor of said variable transformer, means for applying alternating current to said first mentioned pair of coils, a balanced output circuit, one end of each of said second pair of coils being connected together and to a neutral point in said output circuit, the other ends of said second pair of coils being connected to points on said output circuit which are adapted to oppositely vary in potential with respect to said neutral point, the relative phase relationship between the input and output alternating currents depending upon the angle of the rotor relative to the stator.

2. A variable phase changing arrangement comprising a pair of inductance coils having a common diameter and disposed at an angle to each other, and forming the stator of a variable transformer, each coil forming part of a tuned circuit, said circuits being so dimensioned that the phase angle between the currents therein when energized by alternating current is equal to the angle between said coils whereby a rotating electromagnetic field is formed, a second pair of mutually perpendicular coils forming the rotor of said variable transformer, means for applying alternating current to said first mentioned pair of coils, a balanced output circuit, one end of each of said second pair of coils being connected together and to a neutral point in said output circuit, the other ends of said second pair of coils being connected to points on said output circuit which are adapted to oppositely vary in potential with respect to said neutral point, the relative phase relationship between the input and output alternating currents depending upon the angle of the'rotor relative to the stator.

3. A variable phase changing arrangement comprising two mutually perpendicular inductance coils each forming part of a tuned circuit, said circuits being resonant at two frequencies on oppositesides of the frequency of the alternating current whose phase is to be adjusted, said two frequencies being such that the phases of the currents in two said coils will be in phase quadrature when said circuits are energized by said alternating current; two further mutually perpendicular coils, said first mentioned two coils forming the stator of a variable transformer and said further two coils forming the rotor of said variable transformer; means for applying said alternating current to the first mentioned two coils and, a balanced output circuit, one end of each of said further pair of coils being connected together and to a neutral point in said output circuit, the other ends of said further pair of coils being connected to points on said output circuit which are adapted to oppositely vary in potential with respect to said neutral point, the arrangement being such that the relative phase between the input and the output alternating currents depends upon the angle of the rotor relative to the stator.

4. A variable phase changing arrangement comprising two mutually perpendicular inductance coils each forming'part of a tuned circuit, said circuits being resonant at two frequencies on opposite sides of the frequency of the alternating current whose phase is to be adjusted, said two frequencies being such that the phases of the currents in two said coils will be in phase quadrature when said circuits are energized by said alternating current; two further mutually perpendicular coils, said first mentioned two coils forming the rotor of a variable transformer and said further two coils forming the stator of said variable transformer; means for applying said alternating current to the first mentioned two coils and, a balanced output circuit, one end of each of said further pair of coils being connected together and to a neutral point in said output circuit, the other ends of said further pair of coils being connected to points on said output circuit which are adapted to oppositely vary in potential with respect to said neutral point, the arrangement being such that the relative phase between the input and the output alternating currents depends upon the angle of the rotor relative to the stator.

5. For use in a phase changing arrangement as claimed in claim 2 a variable transformer comprising two mutually perpendicular similar coils fixed in relation to one another and having a common diameter and two further mutually perpendicular similar coils also with a common diameter and fixed in relation to one another within the first mentioned perpendicular coils, the further coils being rotatable together with respect to the first mentioned coils about an axis which is diametrical to all four coils.

6. An arrangement as claimed in claim 2 wherein each of the two coils to which the alternating current whose phase is to be adjusted is applied, is in parallel with a circuit comprising a resistance in series with a tuning condenser.

7. An arrangement as claim 2 wherein each of the two coils to which the alternating current whose phase is to be adjusted is applied, is in parallel with a circuit comprising a resistance in series with a tuning condenser, said tuning condensers being simultaneously variable.

SHIRLEY VTALDRON HUGH WO-LSELEY FALLO ON. GEORGE MILLINGTON. 

